Clutch mechanism



Apfil 4, 1 939. I A.L. RO SENMUND 2,153,007

' CLUT CH MECEANISM Original Fil ed Oct. 3, 1954 2 Shets-Sheet lINVENTOR.

' A.L.ROSE.NMUND A TTORNEYS.

April 4, 1939. A. L. ROSENMUND- 2,153,007

CLUTCH MECHANISM Original Filed Oct. 3, 1934 -2 Sheets-Sheet -2INVENTOR. ALROSENMUND A TTORNEYS.

Patented Apr. 4, 1939 CLUTCH MECHANISM Alfred L. Rosenmund, Rockaway, N.J., assignor to Stapling Machines 00., a corporation of DelawareOriginal application October 3, 1934, Serial No.

746,655. Divided and this application December 16, 1935, Serial No.54,595. In Canada August 8, 1935 5 Claims.

This invention relates to clutch mechanisms and particularly tomechanisms for clutching a driving drum to a driven shaft.

It is an object of the invention to provide a clutch assembly whichconsists of few parts, is economical to manufacture, is durable, ispositive in its action, and which requires comparatively a small forceto operate.

One illustrative embodiment of the invention is shown in theaccompanying drawings, in which:

Figure l is a side elevation of a driving drum and a clutch assemblyembodying the invention and showing the parts in clutching engagement.

Fig. 2 is a similar View but showing the parts in non-clutchingposition.

Fig. 3 is a sectional view taken on the line 33 of Fig. 1.

In the drawings, the driving drum is designated I and the driven shaftis designated 2. Keyed to the shaft 2 is: a clutch collar 3 which issecured to one end of a clutch band 4. Secured to the other end of theclutch band 4 is a block 5 which bears against the peripheral surface ofa collar 6 loosely mounted on a hub I of clutch collar 3. Collar 6 isconnected to collar 3 by a spring 8 which normally holds collar 5 in theposition shown in Fig. 1. In this position, the cam-like peripheral.surface Ii of collar 6 acting through the block 5 forces clutch band 4into clutching contact with drum I.

For moving collar 6 against the action of spring 8 to release thepressure on block 5 and break the clutch connection between the band 4and the drum I, a buffer arm 9 is provided to engage a shoulder IU ofthe collar Ii.

As shown in Fig. 2, when the buffer 9 comes in contact with shoulderIll, collar 6 is moved against the action of spring 8, thus movingcollar 6 from the position shown in Fig. 1 to the position shown in Fig.2 and permitting the clutch band 4 to move inwardly and out of contactwith the drum I.

Buffer 9 is fixed to a rock shaft II journaled in the frame of anymachine in which the clutch mechanism is employed. One such machine isdisclosed in my copending application Serial No. 746,655 filed October3, 1934, of which this application is a division. The operation of thebuffer 9 is fully described in said copending application.

It should be noted that because of the cam action of the collar 6 on theblock 5 very little force is required in the spring 8 to move that endof the clutch band 4 against drum I and that the clockwise force of drumI again clutch band 4 tends to expand the band 4, thus increasing thefriction and driving power and exerting a self-energizing eifect.

It should be noted also that the clutch band 4 is thin and flexible andsubstantially coextensive with the inner periphery of the drum and thatthe cam 6 which is moved in a clockwise direction, i. e., in thedirection of rotation of the drumforces the rear end of clutch band 4into engagement with drum I and that after this initial engagementbetween the rear end of the band 4 and the drum I the movement of thedrum will immediately expand the flexible band 4 throughout its entirelength and thus produce an increasing frictional pressure many timesgreater than the initial pressure applied by the spring 8. Because of.this arrangement the spring 8 which moves the cam 6 need only be strongenough to move the rear end of band 4 into contact with the drum I.There-after the moving drum acting on the rear end of the band expandsthe band and forces it into clutching engagement with the drumthroughout the entire length of the band.

The expression rear end of the clutch band as used in the specificationand claims means the rear end of the clutch band in its direction ofmovement with the drum, i. e., in a clockwise direction in theillustrative device.

The operation of the clutch assembly should be clear from the foregoingdescription. With the parts shown in the position in Fig. 2, the buffer9 is rocked out of contact with the shoulder I0. Thereupon spring 8moves collar 6 from the position shown in Fig. 2 to the position shownin Fig. 1. This movement of collar 6 through the action of its camsurface against block 5 forces clutch band 4 into clutching engagementwith drum I. So long as buffer 9 is held out of engagement with shoulderII], the driving drum I will continue to rotate driven shaft 2. When,however, buffer 9 is moved into the path of rotation of shoulder IE! itwill engage the shoulder and stop rotation of the collar 6. Continuedmovement of block 5 will move it toward the low point of cam surface 6of collar 6, thus permitting clutch band 4 to move away from drum I andbreak its clutching engagement therewith.

It will be understood that the invention is not to be limited to thespecific embodiment shown for purposes of illustration as the inventionmay be variously embodied without departing from the invention.

It will also be understood that all of the inventive features need notbe used co-njointly as they may be used in various combinations asdefined in the sub-joined claims.

I claim:

1. In combination with a driving drum and a driven shaft, clutchmechanism comprising a flexible clutch band, a block secured to the rearend thereof, a clutch collar secured to the other end of the clutch bandand keyed to the driven shaft, a second clutch collar rotatably mountedon the hub of the first clutch collar and having a cam surface to engagethe block, a spring connection between the two collars to press the camsurface of the second collar against the block to force the clutch bandinto clutching engagement with the drum, and means to move the sec-- ondclutch collar against the action of the spring to release the pressureon the clutch band.

2. In combination with a driving drum and a driven shaft, a clutchmechanism comprising a flexible clutch band, a clutch collar secured tothe front end of the clutch band and keyed to the driven shaft, a secondclutch collar rotatably mounted on the hub of the first clutch collarand having a cam surface engaging the rear end of the clutch band, aspring connection between the two collars to cause the cam surface ofthe second clutch collar to press the rear end of the clutch band towardthe drum, and means to move the second clutch collar against the actionof said spring to release the pressure on the clutch band.

3. Means for clutching a driving drum to a driven shaft comprising, aflexible clutch band, a clutch collar keyed to the driven shaft andsecured to the front end of the clutch band, a second clutch collarrotatably mounted on a hub of the first clutch collar and having a camsurface adapted to engage the rear end of the clutch band, spring meansconnecting the two collars and normally pressing the cam surface againstthe rear end of the clutch band to force it into clutching engagementwith the drum, and means for moving the second clutch collar against theaction of the spring means to release the pressure on the clutch band.

4. In combination with a driving element and a driven element, clutchmechanism comprising a flexible clutch band the front end of which isconnected to the driven element and the rear end of which carries ablock, and means to move said band into and out of clutching engagement;said means including a cam member rotatable about the driven element andadapted when in one position to engage the block and force the rear endof the band into clutching engagement with the driving element, andmeans to control the movement of the cam member.

5. In combination with a driving drum and a driven shaft, clutchmechanism comprising a flexible clutch band located within the drivingdrum and having an overall length which is less than the insidecircumference of the drum, means connecting the driven shaft to theclutch band at a point adjacent the forward end of the clutch band whileleaving the clutch band free of connection with the driven shaftrearwardly of said point of connection, and cam means perable adjacentthe rear end of the clutch band to press the band at that point againstthe'driving drum whereby movement of the driving drum will force theclutch band into clutching engagement with the driving drum between thepoint of application of the pressure and the point of connection to thedriven shaft.

ALFRED L. ROSENMUND.

. CERTIFICATE OF CORRECTION. Patent N00 2,155,007. A r-11 LL, 19 9,

ALFRED L. ROSENMUND.

It is hereby certified that error appears in the printed specificationof the above nmnberedgatent requiring correction as follows: Page 1,first column, line 55, for "6 read 6;. same page, second column, line 1,for the word "again" read against; lines 8 and 19, for "cam 6" read cam6 and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this lth, day of May, A. D. 1959.

Henry Van Arsdale (Seal) Acting onmissioner of Patents.

